It will depend on the OS version, JDK version used. Also might differ based on system is 32-bit or 64-bit.
For Oracle 11g forms & reports (11.1.2.1.0) on Windows 7 with 32-bit, Oracle weblogic server 10.3.6+ will work.

Refer to - http://www.oracle.com/technetwork/developer-tools/forms/oracle-forms-111210certmatrix-1886127.xls for the correct version.